An existing electrochromic display device needs electrochromic materials with three colors to realize color display. As shown in FIG. 1A-FIG. 1b, the incident light is usually white light; when the electrochromic materials are powered on, the red electrochromic material 11, green electrochromic material 12 and blue electrochromic material 13 present red, green and blue states respectively, thereby transmitting red light, green light and blue light, realizing color display; when the electrochromic materials are powered off, transparent display is realized.
The existing electrochromic display device has the following defects: it can not realize black display (i.e., presenting a dark state); moreover, since the luminous efficiencies of the red, green and blue electrochromic materials are inconsistent, driving of the color electrochromic display device is relatively complicated.